Apparatus and method for plasma assisted deposition

ABSTRACT

Embodiments of the present invention relate to an apparatus and method of plasma assisted deposition by generation of a plasma adjacent a processing region. One embodiment of the apparatus comprises a substrate processing chamber including a top shower plate, a power source coupled to the top shower plate, a bottom shower plate, and an insulator disposed between the top shower plate and the bottom shower plate. In one aspect, the power source is adapted to selectively provide power to the top shower plate to generate a plasma from the gases between the top shower plate and the bottom shower plate. In another embodiment, a power source is coupled to the top shower plate and the bottom shower plate to generate a plasma between the bottom shower plate and the substrate support. One embodiment of the method comprises performing in a single chamber one or more of the processes including, but not limited to, cyclical layer deposition, combined cyclical layer deposition and plasma-enhanced chemical vapor deposition; plasma-enhanced chemical vapor deposition; and/or chemical vapor deposition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. patent application Ser. No.10/197,940, filed Jul. 16, 2002 and U.S. Provisional Patent ApplicationSer. No. 60/352,191, filed Jan. 26, 2002, which are both hereinincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to an apparatusand method for plasma assisted deposition. More particularly,embodiments of the present invention relate to an apparatus and methodof plasma assisted deposition by generation of a plasma adjacent aprocessing region.

2. Description of the Related Art

Reliably producing sub-micron and smaller features is one of the keytechnologies for the next generation of very large scale integration(VLSI) and ultra large scale integration (ULSI) of semiconductordevices. However, as the fringes of circuit technology are pressed, theshrinking dimensions of interconnects in VLSI and ULSI technology haveplaced additional demands on the processing capabilities. The multilevelinterconnects that lie at the heart of this technology require preciseprocessing of high aspect ratio features, such as vias and otherinterconnects. Reliable formation of these interconnects is veryimportant to VLSI and ULSI success and to the continued effort toincrease circuit density and quality of individual substrates.

As circuit densities increase, the widths of vias, contacts and otherfeatures, as well as the dielectric materials between them, decrease tosub-micron dimensions (e.g., less than 0.20 micrometers or less),whereas the thickness of the dielectric layers remains substantiallyconstant, with the result that the aspect ratios for the features, i.e.,their height divided by width, increases. Many traditional depositionprocesses have difficulty filling sub-micron structures. Therefore,there is a great amount of ongoing effort being directed at theformation of substantially void-free and seam-free sub-micron featureshaving high aspect ratios.

Atomic layer deposition is one deposition technique being explored forthe deposition of material layers over features having high aspectratios. One example of atomic layer deposition comprises the sequentialintroduction of pulses of gases. For instance, one cycle for thesequential introduction of pulses of gases may comprise a pulse of afirst reactant gas, followed by a pulse of a purge gas and/or a pumpevacuation, followed by a pulse of a second reactant gas, and followedby a pulse of a purge gas and/or a pump evacuation. Sequentialintroduction of separate pulses of the first reactant and the secondreactant is intended to result in the alternating self-limitingadsorption of monolayers of the reactants on the surface of thesubstrate and, thus, forms a monolayer of material for each cycle. Thecycle is repeated to a desired thickness of the deposited material. Apulse of a purge gas and/or a pump evacuation between the pulses of thefirst reactant gas and the pulses of the second reactant gas is intendedto promote reaction of the first reactant gas and the second reactantgas at the surface of a substrate by limiting gas phase reactions.

FIG. 1 is a schematic cross-sectional view of a prior art chamber 10adapted for chemical vapor deposition. The chamber 10 includes ashowerhead 40 and a substrate support 32 for supporting a substrate 36.The showerhead 40 has a central gas inlet 44 for the injection of gasesand has a plurality of holes 42 to accommodate the flow of gasestherethrough. A power source 70, such as an RF power source, is coupledto the showerhead 40 to create an electric field between the shower head40 and the substrate support 32 generating a plasma 80 therebetween. Oneproblem with the use of prior chambers, such as chamber 10, for atomiclayer deposition requiring a plasma 80 is that the plasma 80 may etch orremove deposited materials on the surface of the substrate 36 due to theion bombardment or sputtering by the plasma 80 of the deposited materialon the substrate 36 which is particularly detrimental in atomic layerdeposition in which a monolayer of material is desired to be depositedper cycle of gases.

Prior attempts to perform atomic layer deposition also includegenerating a plasma through a remote plasma source separate from theprocessing chamber and directing the atomic species into the processingchamber for reaction. One problem associated with these prior attemptsis that the atomic species may easily recombine preventing the reactionof the atomic species on the surface of the substrate.

Thus, there is a need for an improved apparatus and method of generatinga plasma in deposition processes.

SUMMARY OF THE INVENTION

Embodiments of the present invention generally relate to an apparatusand method for plasma assisted deposition. More particularly,embodiments of the present invention relate to an apparatus and methodof plasma assisted deposition by generation of a plasma adjacent aprocessing region. One embodiment of the apparatus comprises a substrateprocessing chamber including a top shower plate, a power source coupledto the top shower plate, a bottom shower plate, and an insulatordisposed between the top shower plate and the bottom shower plate. Inone aspect, the power source is adapted to selectively provide power tothe top shower plate to generate a plasma from the gases between the topshower plate and the bottom shower plate. In another embodiment, a powersource is coupled to the top shower plate and the bottom shower plate togenerate a plasma between the bottom shower plate and the substratesupport. In still another embodiment, a power source is coupled to thetop shower plate and to the bottom shower plate to selectively providepower to the top shower plate or to the top and bottom shower plate toselectively generate a plasma from the gases between the top showerplate and the bottom shower plate or from the gases between the bottomshower plate and the substrate support.

One embodiment of the method comprises performing in a single chamberone or more of the processes including, but not limited to, cyclicallayer deposition, combined cyclical layer deposition and plasma-enhancedchemical vapor deposition; plasma-enhanced chemical vapor deposition;and/or chemical vapor deposition.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the features of the present invention areattained and can be understood in detail, a more particular descriptionof the invention, briefly summarized above, may be had by reference tothe embodiments thereof which are illustrated in the appended drawings.

It is to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 is a schematic cross-sectional view of a prior art chamberadapted for plasma deposition.

FIG. 2 is a schematic cross-sectional view of one embodiment of achamber adapted to generate a plasma within the gas distribution systemof the processing chamber.

FIG. 3 is a schematic partial cross-sectional view of a portion of thegas box, a portion of the top shower plate, and a portion of the bottomshower plate of FIG. 2.

FIG. 4 is a schematic exploded perspective view of a top shower plate, agas conduit, and a first piece and a second piece of a bottom showerplate.

FIG. 5 is a schematic exploded cross-sectional view of a top showerplate, the gas conduit, and a first piece and a second piece of thebottom shower plate.

FIG. 6 is a graph of an exemplary process illustrating the controlsignals for sequentially providing a titanium containing compound and ahydrogen plasma.

FIG. 7 is a graph of an exemplary process illustrating the controlsignals for sequentially providing a titanium containing compound and ahydrogen/nitrogen plasma.

FIG. 8 is a graph of an exemplary process illustrating the controlsignals for sequentially providing a titanium containing compound and anitrogen containing gas to deposit a titanium nitride layer.

FIG. 9 is a graph of one exemplary process illustrating the controlsignals for plasma-enhanced chemical vapor deposition of a titaniumlayer.

FIG. 10 is a graph of one exemplary process illustrating the controlsignals for a combination of cyclical layer deposition andplasma-enhanced chemical vapor deposition of a titanium layer.

FIG. 11 is a chart of exemplary embodiments of processes which may beperformed in the chamber shown in FIG. 2.

FIG. 12A is a schematic cross-sectional view of one embodiment of aspecific application utilizing a titanium layer and a titanium nitridelayer together at one stage in the fabrication of an integrated circuit.

FIG. 12B is a schematic cross-sectional view of another embodiment of aspecific application utilizing a titanium layer and a titanium nitridelayer together at one stage in the fabrication of an integrated circuit.

DETAILED DESCRIPTION

Process Chambers

FIG. 2 is a schematic cross-sectional view of one embodiment of achamber 100 adapted to generate a plasma within the gas distributionsystem of the processing chamber. The chamber 100 comprises a chamberbody 102 having a liner 104 disposed therein. An opening 108 in thechamber 100 provides access for a robot (not shown) to deliver andretrieve substrates 110, such as, for example, 200 mm semiconductorwafer, 300 mm semiconductor wafers or glass substrates, to the chamber100.

A substrate support 112 supports the substrate 110 on a substratereceiving surface 111 in the chamber 100. The substrate support 112 ismounted to a lift motor 114 to raise and lower the substrate support 112and a substrate 110 disposed thereon. A lift plate 116 connected to alift motor 118 is mounted in the chamber and raises and lowers pins 120movably disposed through the substrate support 112. The pins 120 raiseand lower the substrate 110 over the surface of the substrate support112.

The substrate support 112 may be heated to heat the substrate 110disposed thereon. For example, the substrate support 112 may have anembedded heating element 122 to resistively heat the substrate support112 by applying an electric current from a power supply (not shown). Atemperature sensor 126, such as a thermocouple, may be embedded in thesubstrate support 112 to monitor the temperature of the substratesupport 112. For example, a measured temperature may be used in afeedback loop to control electric current applied to the heating element122 from a power supply (not shown), such that the substrate temperaturecan be maintained or controlled at a desired temperature or within adesired temperature range. Alternatively, the substrate 110 may beheated using radiant heat, such as by lamps.

A gas distribution system 130 is disposed at an upper portion of thechamber body 102 to provide a gas, such as a process gas and/or a purgegas, to the chamber 100. The gas distribution system 130 may act as achamber lid of the chamber body 102. The gas distribution system 130comprises a gas box 132, a top shower plate 160 positioned below the gasbox 132, and a bottom shower plate 170 positioned below the top showerplate 160. The gas distribution system 130 is adapted to provide gasflows to the substrate receiving surface 111.

The top shower plate 160 is separated from the bottom shower plate 170by an insulator 164 to electrically insulate the top shower plate 160from the bottom shower plate 170. The insulator 164 is made of aninsulating material, such as quartz, Teflon™, Vespel™, ceramics, otherpolymers, and other materials. The bottom shower plate 170 may bedisposed on an upper portion of the chamber body 102, such as on a lidrim 166 disposed on the chamber body 102. In one embodiment, the lid rim166 comprises an insulating material to electrically insulate the bottomshower plate 170 from the chamber body 102.

FIG. 3 is a schematic partial cross-sectional view of a portion of thegas box 132, a portion of the top shower plate 160, and a portion of thebottom shower plate 170 of FIG. 2. In reference to FIG. 2 and FIG. 3,the gas box 132 comprises a central gas channel 137 and a plurality ofouter gas channels 143. The central gas channel 137 provides onediscrete path for the flow of one or more gases through the gas box 132while the outer channels 143 provides another discrete path for the flowof one or more gases through the gas box 132. The central gas channel137 is coupled to a first gas source 135 (FIG. 2) through valve 136(FIG. 2). The central gas channel 137 has a first gas outlet 138 and isadapted to deliver a first gas from the first gas source 135 to a gasconduit 210. The term “gas” as used herein is intended to mean a singlegas or a gas mixture. The outer gas channels 143 are coupled to a secondgas source 141 (FIG. 2) through valve 142 (FIG. 2). The outer gaschannels 143 have second gas outlets 144 and are adapted to deliver asecond gas from the second gas source 141 to the top shower plate 160.Preferably, the second gas outlets 144 of the outer gas channels 143 areadapted to deliver the second gas proximate a central portion of the topshower plate. Gas sources 135, 141 may be adapted to store a gas orliquid precursor in a cooled, heated, or ambient environment. The valves136, 142 control delivery of the first gas and the second gas into thecentral gas channel 137 and the outer gas channels 143 respectively andmay be electrically controlled valves, pneumatically controlled valves,piezoelectric valves, or other suitable valves. In another embodiment,the outer gas channels 143 may comprise a plurality of discrete flowpaths for the flow of a plurality of gases through the gas box 132 byseparately coupling separate gas sources to a particular outer gaschannel.

The gas box 132 may further comprise a cooling/heating channel tocontrol the temperature of the gas distribution system 130 by providinga cooling fluid or a heating fluid to the gas box 132 depending on theparticular process being performed in the chamber 100.

Referring to FIG. 3, the top shower plate 160 has a plurality of holes162 to accommodate a gas flow therethrough from the outer gas channels143 of the gas box 132 to the bottom shower plate 170. The gas conduit210 is disposed through an aperture 163 in the top shower plate 160 andis disposed on the bottom shower plate 170. The gas conduit 210 ispreferably made of an insulating material, such as quartz, Teflon™,Vespel™, ceramics, other polymers, and other materials, to preventelectrical coupling of the top shower plate 160 and the bottom showerplate 170.

The bottom shower plate 170 comprises a first piece 172 connected to asecond piece 180. The first piece 172 has a plurality of holes 174 toprovide a flow of a gas therethrough. The second piece 180 comprises aplurality of columns 182 having column holes 183 formed therethrough anda plurality of grooves 184 having groove holes 185 formed therethrough.The top surface of the columns 182 are connected to the bottom surfaceof the first piece 172 so that the column holes 183 align with the holes174 of the first piece 172. Therefore, one discrete passageway isprovided through the holes of the first piece 172 and through the columnholes 183 of the columns 182 to deliver a gas flow from the top showerplate 160 to the substrate receiving surface 111. An aperture 175 isformed through the first piece 172 and aligns with the grooves on thesecond piece 180. Therefore, another discrete passageway is providedthrough the aperture 175 of the first piece 172 and through the grooves184 and groove holes 185 of the second piece 180 to deliver a gas flowfrom the gas conduit 210 to the substrate receiving surface 111. In oneembodiment, the first piece 172 and the second piece 180 are brazed ordiffusion-bonded together to prevent leakage between the discretepassageways.

FIG. 4 is a schematic exploded perspective view of the gas conduit 210,the top shower plate 160, and the first piece 172 and the second piece180 of the bottom shower plate 170. FIG. 5 is a schematic explodedcross-sectional view of the gas conduit 210, the top shower plate 160,and the first piece 172 and the second piece 180 of the bottom showerplate 170. In reference to FIG. 4 and FIG. 5, the gas conduit 210 isdisposed through the aperture 163 of the top shower plate 160 andcoupled to the aperture 175 of the first piece 172 of the bottom showerplate 170. Preferably, there are no columns 183 directly below theaperture 175 to allow the flow of a gas from the gas conduit 210 throughthe aperture 175 to the grooves 184 of bottom shower plate 170. Thecolumns 182 and grooves 184 may be arranged so that the grooves 184 arein communication with one another. In one embodiment, the columns 182and grooves 184 are formed by machining the grooves 184 into the secondpiece 180. Other embodiments of the bottom shower plate include a firstpiece having grooves and columns and a second piece comprising aplurality of holes.

The top shower plate 160, the bottom shower plate 170, and the gas box132 may be made of stainless steel, aluminum, nickel-plated metal,nickel-plated aluminum, nickel, nickel alloys (such as INCONEL®,HASTELLOY®), graphite, other suitable materials, and combinationsthereof. In general, the top shower plate 160 and the bottom showerplate 170 are sized and shaped substantially equal to or larger than thesubstrate receiving surface 111.

Referring to FIG. 2, a power source 190 may be coupled to the top showerplate 160 through the gas box 132 to provide a power electrode and thebottom shower plate 170 may be grounded to provide a ground electrode.The power source 190 may be an RF or DC power source. An electric fieldmay be established between the top shower plate 160 and the bottomshower plate 170 to generate a plasma from the gases introduced betweenthe top shower plate 160 and the bottom shower plate 170.

In another embodiment, the power source 190 may be coupled to the topshower plate 160 and the bottom shower plate 170. A switch device 192 iscoupled between the power source 190 and the bottom shower plate 170 toselectively power or ground the bottom shower plate 170. In one aspect,power source 190 provides power to the top shower plate 160 and thebottom shower plate 170 so that the top shower plate 160 and the bottomshower plate 170 are at the same or substantially the same potential.With a grounded substrate support 112, the top shower plate 160 and thebottom shower plate 170 act as one electrode and the substrate support112 acts as another electrode of spaced apart electrodes in which anelectric field is established between the bottom shower plate 170 andthe substrate support 112 to generate a plasma from the gases introducedbetween the bottom shower plate 170 and the substrate support 112.Therefore, the bottom shower plate 170 may be selectively powered orgrounded to selectively generate a plasma between the top shower plate160 and the bottom shower plate 170 or between the bottom shower plate170 and the substrate support 112.

In still another embodiment, the substrate support 112 may beselectively powered or grounded in addition to the bottom shower plate170 being selectively powered or grounded to provide a plasma betweenthe bottom shower plate 170 and the substrate support 112.

A vacuum system 196 is in communication with a pumping channel 197formed in the chamber body 102 to evacuate gases from the chamber 100and to help maintain a desired pressure or a desired pressure rangeinside the chamber 100.

Control unit 176 may be coupled to the chamber 100 to control processingconditions. For example, the control unit 176 may be connected to thevalves 136, 142 to control the flow of gases through the gasdistribution system 130 during different stages of a substrate processsequence. In another example, the control unit 176 may be connected tothe power source 190 to control generation of a plasma. In anotherexample, the control unit 176 may be connected to the embedded heatingelement 122 to control the temperature of the substrate support 112. Thecontrol unit 176 may be configured to be responsible for automatedcontrol of other activities used in substrate processing, such assubstrate transport, chamber evacuation, and other activities, some ofwhich are described elsewhere herein.

Referring to FIG. 2 and FIG. 3, in operation, a substrate 110 isdelivered to the chamber 100 through the opening 108 by a robot (notshown). The substrate 110 is positioned on the substrate support 112through cooperation of the lift pins 120 and the robot. The substratesupport 112 raises the substrate 110 into close opposition to the bottomshower plate 170. A first gas and/or a second gas is injected into thechamber 100 through the central gas channel 137 and/or the outer gaschannels 143 of the gas box 132. If a first gas is injected, the firstgas flows though the central gas channel 137 of the gas box 132 to thegas conduit 210, through the gas conduit 210 to the bottom shower plate170, and through the grooves 184 and groove holes 185 of the bottomshower plate 170 to the substrate receiving surface 111. If a second gasis injected, the second gas flows through the outer gas channels 143 ofthe gas box 132 to the top shower plate 160, through the holes 162 ofthe top shower plate 160 to the bottom shower plate 170, and through thecolumn holes 183 of the bottom shower plate 170 to the substratereceiving surface 111. Excess gas, by-products, etc. flow into thepumping channel 197 and are then exhausted from the chamber by a vacuumsystem 196. Since the first gas and the second gas flow through the gasdistribution system 130 from a central portion of the gas box 132outward to a peripheral region of the bottom shower plate 170, purgingof the gases from the gas distribution system 130 is faster than otherdual gas delivery showerheads in which one or more gas flows aredelivered from a perimeter portion of the showerhead to a centralportion of the showerhead.

In one aspect, an electric field may be established between the topshower plate 160 and the bottom shower plate 170 to generate a plasmafrom a gas between the top shower plate 160 and the bottom shower plate170. Atomic species may flow through the column holes 183 of the bottomshower plate 170 to the substrate receiving surface 111. In anotheraspect, an electric field may be created between the bottom shower plate170 and the substrate support 112 to generate a plasma from a gasbetween the bottom shower plate 170 and the substrate support 112.

In one aspect, generating a plasma between the top shower plate 160 andthe bottom shower plate 170 may be used to advantage in cyclical layerdeposition. The term “cyclical layer deposition” as used herein refersto the sequential introduction of one or more compounds to deposit athin layer of material over a structure and includes processingtechniques. Compounds can be reactants, reductants, precursors,catalysts, plasma species, and mixtures thereof. Sequentially providingcompounds may result in the formation of thin layers of material over asubstrate structure. Each thin layer of material may be less than amonolayer, a monolayer, or more than a monolayer of material. Thesequential introduction of compounds may be repeated to deposit aplurality of thin layers forming a conformal film to a desiredthickness. Since a plasma is not generated between a showerhead and thesubstrate support, there is less of an etching effect or removal effectof the plasma on deposited materials on the substrate 110 due to ionbombardment or sputtering by the plasma. In addition, the gasdistribution system 130 may be used to advantage in cyclical layerdeposition because the first gas and the second gas may be separatelydelivered through the gas distribution system 130. Thus, gas phasereactions between the first gas and the second gas may be reduced andprevented in components of the gas distribution system 130. In oneaspect, because a plasma is generated between the top shower plate 160and the bottom shower plate 170 (as opposed to a remote plasma source),a smaller amount of atomic species recombine to gas compounds (i.e.,atomic hydrogen species recombining into hydrogen gas). Atomic speciestravel a shorter distance from the bottom shower plate 170 to thesubstrate receiving surface 111 in comparison to the distance atomicspecies must travel from a remote plasma source to the substratereceiving surface 111. Because of a reduction of the “recombinationeffect,” a greater amount of atomic species for a particular process,such as hydrogen species, are directed to the substrate receivingsurface 111 increasing the throughput of a deposition process, such as acyclical layer deposition process.

In reference to FIG. 3, in one specific embodiment, the column holes 183of the bottom shower plate 170 have a diameter less than about 100 mils.If the column holes 183 of the bottom shower plate 170 are too large,then the plasma will still have an ion bombardment/sputter effect ondeposited materials. If the column holes 183 are too small, then therewill still be a recombination effect of atomic species recombining togas compounds due to gas phase recombination and surface recombinationon the surfaces of the bottom shower plate 170. In one specificembodiment, the distance between the top shower plate 160 and the bottomshower plate 170 is between about 100 mils and about 800 mils. If thedistance between the top shower plate 160 and bottom shower plate 170 istoo short, arcing may occur. In one specific embodiment, the distancebetween the bottom shower plate 170 and the substrate support 112 duringone technique of substrate processing (i.e. cyclical layer deposition)is between about 100 mils and about 1,000 mils.

In reference to FIG. 2, in one aspect, generating a plasma between thebottom shower plate 170 and the substrate support 112 may be used toadvantage in chemical vapor deposition processes. The bottom showerplate 170 provides two separate uniform gas flows to the substratereceiving surface 111. Since chemical vapor deposition processes occurin more of a gas phase and/or thermal decomposition process rather thanan adsorption process, the etching effect of the plasma generated inthis region is not as detrimental to film deposition as in cyclicallayer deposition. In addition, the bottom shower plate 170 provides auniform mixture of the first gas and the second gas between the bottomshower plate 170 and the substrate support 112 which may be beneficialin providing a uniform plasma for chemical vapor deposition.

Other embodiments of chamber 100 are also within the scope of thepresent disclosure. For example, the bottom shower plate may compriseother dual gas delivery shower plates. For instance, a dual gas deliveryshower plate may be adapted to receive a gas at a peripheral portion ofthe shower plate, such as the shower plate disclosed in U.S. Pat. No.6,086,677, to Umotoy et al. entitled “Dual Gas Faceplate for aShowerhead in a Semiconductor Processing System,” disclosed is U.S. Pat.No. 6,302,964, to Umotoy et al. entitled “One-Piece Dual Gas Faceplatefor a Showerhead in a Semiconductor Wafer Processing System”, ordisclosed in U.S. patent application Ser. No. 10/033,544, to Hytros etal. entitled “Dual-Gas Delivery System for Chemical Vapor DepositionProcesses, which are all incorporated by reference in their entirety tothe extent not inconsistent with the present disclosure. Another exampleof a dual gas delivery shower plate is disclosed in U.S. Pat. No.6,148,761, to Majewski et al. entitled “Dual Channel Gas DistributionPlate.” In other embodiments, the chamber 100 may comprise a bottomshower plate with only a single gas channel (i.e. a plate having aplurality of holes formed therethrough).

Deposition Processes

Chamber 100 as described in FIGS. 2-5 may be used to implement thefollowing exemplary process for deposition of titanium (Ti), titaniumnitride (TiN), tantalum (Ta), tantalum nitride, tungsten (W), tungstennitride (WN), other refractory metals, other refractory metal nitrides,other refractory metal compounds, other materials, and combinationsthereof. Chamber 100 may also be used to implement other processes. Forexample, chamber 100 may be used to advantage in the deposition ofdielectric materials, such as titanium oxide and titanium carbide. Inaddition, chamber 100 may be used to advantage in the deposition oflow-k materials utilizing an oxygen plasma. It should also be understoodthat the following processes may be performed in other chambers as well.

A. Cyclical Layer Deposition of a Refractory Metal Laver

Chamber 100 may be used to deposit a refractory metal layer by cyclicallayer deposition. In one embodiment, cyclical layer deposition of arefractory metal layer comprises sequentially providing a refractorymetal containing compound and a hydrogen plasma in process chamber 100.Sequentially providing a refractory metal containing compound and ahydrogen plasma may result in the alternating adsorption of a refractorymetal containing compound and reduction of the refractory metalcontaining compound by atomic hydrogen to form thin layers of arefractory metal on a substrate structure. The terms “adsorption” or“adsorb” as used herein are defined to include chemisorption,physisorption, or any attractive and/or bonding forces which may be atwork and/or which may contribute to the bonding, reaction, adherence, oroccupation of a portion of an exposed surface of a substrate structure.In certain aspects, embodiments of cyclical layer deposition provideimproved conformal coverage over substrate structures in comparison toconventional chemical vapor deposition. In addition, in certain aspects,embodiments of cyclical layer deposition provide a deposited layer withless incorporated impurities.

For clarity reasons, deposition of a refractory metal layer will bedescribed in more detail in reference to one embodiment of a refractorymetal layer comprising a titanium layer. Deposition of a tantalum layeror tungsten layer would follow similar processes. FIG. 6 is a graph ofan exemplary process illustrating the control signals for sequentiallyproviding a titanium containing compound and a hydrogen plasma inprocess chamber 100 (FIG. 2) to deposit a titanium layer. One cycle 510of sequentially providing a titanium containing compound and a hydrogenplasma to process chamber 100 (FIG. 2) comprises providing a continuousflow 520 of a hydrogen containing gas 522, such as hydrogen gas (H₂), tothe chamber through the outer gas channels 143 (FIG. 2), through the topshower plate 160 (FIG. 3), and through the column holes 183 of thebottom shower plate 170 (FIG. 3) to the substrate receiving surface 111(FIG. 2). During the continuous flow 520 of the hydrogen containing gas522, a pulse 530 of a titanium containing compound 532, such as TiCl₄,is introduced to the chamber through the central gas channel 137 (FIG.2) of the gas distribution system 130, through the gas conduit 210 (FIG.3), and through the groove holes 185 of the bottom shower plate 170(FIG. 3) to the substrate receiving surface 111 (FIG. 2). The titaniumcontaining compound 532 may be introduced alone or with the aid of acarrier gas, such as argon gas, helium gas, hydrogen gas, orcombinations thereof. If a carrier gas is used, the carrier gas may alsobe pulsed into the chamber 100 (FIG. 2) or the carrier gas may be acontinuous flow in which the titanium containing compound 532 is dosedinto the stream of the carrier gas. Preferably, a continuous flow of acarrier gas is used. After the pulse 530 of the titanium containingcompound 532, the flow 520 of the hydrogen containing gas 522 continuesto the chamber to act as a purge gas 524 to reduce gas phase reactions(i.e. between the titanium containing compound 532 and the hydrogenplasma 526 introduced thereafter). Then during the continuous flow 520of the hydrogen containing gas 522, a pulse 540 of plasma power 542,such as an RF power, is provided to the top shower plate 160 (FIG. 2) togenerate a hydrogen plasma 526 from the flow 520 of the hydrogencontaining gas 522 between the top shower plate 160 and the bottomshower plate 170 (FIG. 2). The generated atomic hydrogen flows throughthe column holes 183 of the bottom shower plate 170 (FIG. 3) to thesubstrate receiving surface 111 (FIG. 2). After the pulse 540 of plasmapower 542, the flow 520 of the hydrogen containing gas 522 continues tothe chamber to act as a purge gas 528 to reduce gas phase reactionsbetween the titanium containing compound 532 and the hydrogen plasma526. The cycle 510 may be repeated to a desired thickness of thetitanium layer.

In general, hydrogen gas does not substantially react with titaniumprecursors, such as TiCl₄, even at high heater temperatures. Therefore,a hydrogen plasma (i.e., atomic hydrogen) is necessary for the reactionof a titanium containing compound to deposit titanium. In one aspect,the continuous flow 520 of the hydrogen containing gas 522 allows forthe gas delivery system and associated valve design to be simpler andmore efficient since valves, such as valve 142, does not need to beconstantly turned on and off to pulse the hydrogen containing gas intothe chamber.

In another embodiment, the above method may be performed in chamber 100(FIG. 2) with a gas conduit, similar to the gas conduit as shown in FIG.3, which only extends between the central gas channel 137 and throughthe aperture 163 of the top shower 160 plate. As a consequence, thetitanium containing compound 532 flows between the top shower plate 160and the bottom shower plate 170 and through the column holes of thebottom shower plate 170. Since a hydrogen plasma 526 and a titaniumcontaining compound 532 are introduced at different times between thetop shower plate 160 and the bottom shower plate 170, gas phasereactions between the hydrogen plasma 526 and the titanium containingcompound 532 are minimal.

Not wishing to be bound by theory, it is believed that reaction of thetitanium containing compound 532 and the hydrogen plasma 526 isself-limiting in that only one monolayer or less of the titaniumcontaining compound 532 may be adsorbed onto the substrate surface toform one monolayer or less of titanium due to the purge gas separatingthe pulses of the titanium containing compound 532 and pulses of thehydrogen plasma 526. In other embodiments, the sequence of gas deliverymay be varied to provide a partial self-limiting deposition process or anon-self-limiting deposition process. For example, the pulse 530 of thetitanium containing compound 532 may be partially overlapped with thepulse 540 of plasma power 542 to provide a combined mode of deposition(i.e. a combined adsorption process and gas-phase/thermal co-reactionprocess between the titanium containing compound and the hydrogenplasma). In another example, the purge gas 524, 528 may only partiallyseparate the pulses of the titanium containing compound 532 and thepulses of the hydrogen plasma 526.

It is understood that the titanium containing compound 532 may also beother titanium based precursors such as titanium iodide (Til₄), titaniumbromide (TiBr₄), or other titanium halides. The titanium containingcompound 532 may also be a metal organic compound such as, for example,tetrakis(dimethylamino)titanium (TDMAT), tetrakis(diethylamino)titanium(TDEAT), among others. The hydrogen containing gas 522 may also be otherreducing gases, such as silane (SiH₄), borane (BH₃), diborane (B₂H₆),triborane (B₃H₉), among others.

One exemplary process of depositing a titanium layer by cyclical layerdeposition in process chamber 100, as described in FIGS. 2-5, comprisesproviding a titanium containing compound comprising titaniumtetrachloride (TiCl₄) for a time period between about 0.1 to about 5.0seconds, preferably less than about 1 second, to the central gas channel137 (FIG. 2). Because the titanium containing compound is provided as apulse it is difficult to determine the corresponding flow rate that thetitanium containing compound is provided. However, it is believed thatthe titanium tetrachloride is provided at a total flow rate betweenabout 5 mg/m to about 500 mg/m. The titanium tetrachloride is providedwith a carrier gas, such as hydrogen gas, helium gas, argon gas, andcombinations thereof, at a flow rate between about 500 sccm and about10,000 sccm. A hydrogen containing gas comprising hydrogen gas (H₂) witha carrier gas, such as helium, argon, or combinations thereof, isprovided at a continuous flow at a total flow rate between about 100sccm and about 5,000 sccm to the outer gas channels 143 (FIG. 2). Theplasma power is provided for a time period between about 0.1 seconds andabout 5.0 seconds, preferably less than about 1 second. The plasma poweris preferably a RF power between about 50 W and about 2,000 W,preferably between 300 W to about 1000 W, at a frequency of 13.56 MHz.The heater temperature preferably is maintained at a temperature rangebetween about 20° C. and about 700° C. , preferably between about 250°C. and about 500° C. In one aspect, it is believed that flowing intitanium tetrachloride at a heater temperature less than about 500° C.reduces the etching effect of the chlorine in the titanium tetrachlorideto materials thereunder. The chamber is maintained at a chamber pressurebetween about 1.0 torr and about 20 torr, and preferably between about2.0 torr and about 10.0 torr. This process provides a titanium layer ina thickness which is believed to be between about 0.2 Å and about 2.0 Åper cycle. The alternating sequence may be repeated until a desiredthickness is achieved. The thickness of the titanium layer may bedeposited to any thickness depending on the particular application.

For the deposition of a refractory metal layer comprising tantalum, atantalum containing compound is used. Tantalum containing compoundsinclude tantalum based precursors such as tantalum pentachloride (TaCl₅)and other tantalum halides and derivatives thereof. Tantalum containingcompounds may also be a metal organic compound such aspentadimethylamino—tantalum (PDMAT; Ta(NMe₂)₅),pentaethylmethylamino—tantalum (PEMAT; Ta[N(C₂H₅CH₃)₂]₅),pentadiethylamino—tantalum (PDEAT; Ta(NEt₂)₅,), and any and all ofderivatives of PDMAT, PEMAT, or PDEAT. Other tantalum containingcompounds include without limitation TBTDET (Ta(NEt₂)₃NC₄H₉ orC₁₆H₃₉N₄Ta). For the deposition of a refractory metal layer comprisingtungsten, a tungsten containing compound is used. Tungsten containingcompounds include tungsten based precursors such as tungstenhexafluoride (WF₆), tungsten hexachloride (WCl₆), and other tungstenhalides and derivatives thereof. Other tungsten containing compoundsinclude without limitation tungsten carbonyl (W(CO)₆).

B. Cyclical Layer Deposition of a Refractory Metal Nitride Layer

Chamber 100 may be used to deposit a refractory metal nitride layer bycyclical layer deposition.

i. Cyclical Layer Deposition of a Refractory Metal Nitride LayerUtilizing a Plasma

In one embodiment, cyclical layer deposition of a refractory metalnitride layer may proceed in a process similar to cyclical layerdeposition of a refractory metal layer. In one embodiment, cyclicallayer deposition of a refractory metal nitride layer comprisessequentially providing a refractory metal containing compound and ahydrogen/nitrogen plasma in process chamber 100. Sequentially providinga refractory metal containing compound and atomic hydrogen/nitrogen mayresult in the alternating adsorption a refractory metal containingcompound and reaction with atomic hydrogen/nitrogen to form thin layersof a refractory metal nitride on a substrate structure. For clarityreasons, deposition of a refractory metal nitride layer will bedescribed in more detail in reference to one embodiment of a refractorymetal nitride layer comprising a titanium nitride layer. Deposition of atantalum nitride layer or tungsten nitride layer would follow similarprocesses.

FIG. 7 is a graph of an exemplary process illustrating the controlsignals for sequentially providing a titanium containing compound and ahydrogen/nitrogen plasma in process chamber 100 (FIG. 2) to deposit atitanium nitride layer. One cycle 810 of sequentially providing atitanium containing compound and a hydrogen/nitrogen plasma to processchamber 100 (FIG. 2) comprises providing a continuous flow 820 of ahydrogen/nitrogen containing gas 822, such as a mixture of hydrogen gas(H₂) and nitrogen gas (N₂), to the chamber 100 (FIG. 2) through theouter gas channels 143 (FIG. 2), through the top shower plate 160 (FIG.3), and through the column holes 183 of the bottom shower plate 170(FIG. 3) to the substrate receiving surface 111 (FIG. 2). During thecontinuous flow 820 of the hydrogen/nitrogen containing gas 822, a pulse830 of a titanium containing compound 832, such as TiCl₄, is introducedto the chamber through the central gas channel 137 (FIG. 2) of the gasdistribution system 130, through the gas conduit 210 (FIG. 3), andthrough the groove holes 185 of the bottom shower plate 170 (FIG. 3) tothe substrate receiving surface 111 (FIG. 2). The titanium containingcompound 832 may be introduced alone or with the aid of a carrier gas,such as argon, helium, hydrogen gas, nitrogen gas, or combinationsthereof. If a carrier gas is used, the carrier gas may also be pulsedinto the chamber 100 (FIG. 2) or the carrier gas may be a continuousflow in which the titanium containing compound 832 is dosed into thestream of the carrier gas. Preferably, a continuous flow of a carriergas is used. After the pulse 830 of the titanium containing compound832, the flow 820 of the hydrogen/nitrogen containing gas 822 continuesto the chamber to act as a purge gas 824 to reduce gas phase reactions(i.e. between the titanium containing compound 832 and thehydrogen/nitrogen plasma 826 introduced thereafter). Then during thecontinuous flow 820 of the hydrogen/nitrogen containing gas 822, a pulse840 of plasma power 842, such as an RF power, is provided to the topshower plate 160 (FIG. 2) to generate a hydrogen/nitrogen plasma 826from the flow 820 of the hydrogen/nitrogen containing gas 822 betweenthe top shower plate 160 and the bottom shower plate 170 (FIG. 2). Thegenerated atomic hydrogen/nitrogen flows through the column holes 183 ofthe bottom shower plate 170 (FIG. 3) to the substrate receiving surface111 (FIG. 2). After the pulse 840 of plasma power 842, the flow 820 ofthe hydrogen/nitrogen containing gas 822 continues to the chamber to actas a purge gas 828 to reduce gas phase reactions between the titaniumcontaining compound 832 and the hydrogen/nitrogen plasma 826. The cycle810 may be repeated to a desired thickness of the titanium nitridelayer.

Not wishing to be bound by theory, it is believed that reaction of thetitanium containing compound 832 and the hydrogen/nitrogen plasma 826 isself-limiting in that only one monolayer or less of the titaniumcontaining compound 832 may be adsorbed onto the substrate surface toform one monolayer or less of titanium nitride due to the purge gasseparating the pulses of the titanium containing compound 832 and pulsesof the hydrogen nitrogen plasma 826. In other embodiments, the sequenceof gas delivery may be varied to provide a partial self-limitingdeposition process or a non-self-limiting deposition process. Forexample, the pulse 830 of the titanium containing compound 832 may bepartially overlapped with the pulse 840 of plasma power 842 to provide acombined mode of deposition (i.e. a combined adsorption process andgas-phase/thermal co-reaction process between the titanium containingcompound and the hydrogen/nitrogen plasma). In another example, thepurge gas 824, 828 may only partially separate the pulses of thetitanium containing compound 832 and the pulses of the hydrogen/nitrogenplasma 826.

It is understood that the titanium containing compound 832 may also beother titanium based precursors, such as other titanium based precursorsdisclosed elsewhere herein. Examples of other hydrogen/nitrogencontaining gases which may also be used to generate a hydrogen/nitrogenplasma include, but are not limited to, ammonia (NH₃), N_(x)H_(y) with xand y being integers (e.g., hydrazine (N₂H₄)); a mixture of hydrogengas, nitrogen gas, and ammonia; other combinations thereof; and othergases or gas mixtures containing hydrogen and nitrogen.

One exemplary process of depositing a titanium nitride layer by cyclicallayer deposition in chamber 100, as described in FIGS. 2-5, comprisesproviding a titanium containing compound comprising titaniumtetrachloride (TiCl₄) for a time period between about 0.1 to about 5.0seconds, preferably less than about 1 second, to the central gas channel137 (FIG. 2). Because the titanium containing compound is provided as apulse it is difficult to determine the corresponding flow rate that thetitanium containing compound is provided. However, it is believed thatthe titanium tetrachloride is provided at a total flow rate betweenabout 5 mg/m to about 500 mg/m. The titanium tetrachloride is providedwith a carrier gas of a hydrogen gas/nitrogen gas mixture at a flow ratebetween about 500 sccm and about 10,000 sccm. A hydrogen/nitrogencontaining gas comprising hydrogen gas (H₂) and nitrogen gas (N₂) with acarrier gas, such as helium, argon, or combinations thereof, is providedat a continuous flow at a total flow rate between about 100 sccm andabout 5,000 sccm to the outer gas channels 143 (FIG. 2). For ahydrogen/nitrogen containing gas comprising hydrogen gas and nitrogengas, the ratio of hydrogen gas to nitrogen gas is between about 0.5:2and about 2:0.5. The plasma power is provided for a time period betweenabout 0.1 seconds and about 5.0 seconds, preferably less than about 1second. The plasma power is preferably a RF power between about 50 W andabout 2,000 W, preferably between 300 W and about 1000 W, at a frequencyof 13.56 MHz. The heater temperature preferably is maintained at atemperature range between about 20° C. and about 700° C., preferablybetween about 250° C. and about 500° C. The chamber is maintained at achamber pressure between about 1.0 torr and about 20 torr, andpreferably between about 2.0 torr and about 10.0 torr. This processprovides a titanium nitride layer in a thickness which is believed to bebetween about 0.2 Å and about 2.0 Å per cycle. The alternating sequencemay be repeated until a desired thickness is achieved. The thickness ofthe titanium nitride layer may be deposited to any thickness dependingon the particular application.

For the deposition of a refractory metal nitride layer comprisingtantalum nitride, a tantalum containing compound is used, such as thetantalum containing compounds described elsewhere herein. For thedeposition of a refractory metal nitride layer comprising tungstennitride, a tungsten containing compound is used, such as the tungstencontaining compounds described elsewhere herein.

ii. Cyclical Layer Deposition of a Refractory Metal Nitride LayerWithout Use of a Plasma

In other embodiments, cyclical layer deposition of a refractory metalnitride layer comprises sequentially providing a refractory metalcontaining compound and a nitrogen containing gas in process chamber 100without the use of a plasma. Sequentially providing a refractory metalcontaining compound and a nitrogen containing gas may result in thealternating adsorption of monolayers of a refractory metal containingcompound and of monolayers of a nitrogen containing compound on asubstrate structure. For clarity reasons, deposition of a refractorymetal nitride layer will be described in more detail in reference to oneembodiment of the refractory metal nitride layer comprising a titaniumnitride layer. Deposition of a tantalum nitride layer or tungstennitride layer would follow similar processes.

FIG. 8 is a graph of an exemplary process illustrating the controlsignals for sequentially providing a titanium containing compound and anitrogen containing gas utilizing process chamber 100 (FIG. 2) todeposit a titanium nitride layer. One cycle 910 of sequentiallyproviding a titanium containing compound and a nitrogen containing gasto the process chamber 100 (FIG. 2) comprises providing a pulse 930 of atitanium containing compound 932, such as TiCl₄, to the chamber 100(FIG. 2) through the central gas channel 137 (FIG. 2) of the gasdistribution system 130, through the gas conduit 210 (FIG. 3), andthrough the groove holes 185 of the bottom shower plate 170 (FIG. 3) tothe substrate receiving surface 111 (FIG. 2). The titanium containingcompound 932 may be introduced alone or with the aid of a carrier gas,such as argon, helium, hydrogen gas, nitrogen gas, or combinationsthereof. If a carrier gas is used, the carrier gas may also be pulsedinto the chamber 100 (FIG. 2) or the carrier gas may be a continuousflow in which the titanium containing compound 932 is dosed into thestream of the carrier gas. Preferably, a continuous flow of a carriergas is used to act as a purge gas to reduce gas phase reactions (i.e.between the titanium containing compound 932 and the nitrogen containinggas 922 introduced thereafter). After the pulse 930 of the titaniumcontaining compound 932, a pulse 920 of a nitrogen containing gas 922,such as ammonia, is introduced through the outer gas channels 143 (FIG.2) of the gas distribution system 130, through the top shower plate 160(FIG. 2), and through the column holes 183 of the bottom shower plate170 (FIG. 3) to the substrate receiving surface 111 (FIG. 2). Thenitrogen containing gas 922 may be introduced alone or with the aid of acarrier gas, such as argon, helium, hydrogen gas, nitrogen gas, orcombinations thereof. If a carrier gas is used, the carrier gas may alsobe pulsed into the chamber 100 (FIG. 2) or the carrier gas may be acontinuous flow in which the nitrogen containing gas 922 is dosed intothe stream of the carrier gas. Preferably, a continuous flow of acarrier gas is used to act as a purge gas to reduce gas phase reactions(i.e. between the titanium containing compound 932 and the nitrogencontaining gas 922). The cycle 910 may be repeated to a desiredthickness of the titanium nitride layer. Because the titanium containingcompound and the nitrogen containing gas are introduced through the gasdistribution system 130 (FIG. 2) through separate paths, gas phasereactions of the titanium containing compound and the nitrogencontaining gas are minimized.

Not wishing to be bound by theory, it is believed that reaction of thetitanium containing compound 932 and the nitrogen containing gas 922 isself-limiting in that only one monolayer or less of the titaniumcontaining compound 932 and one monolayer or less of the nitrogencontaining compound 922 may be adsorbed onto the substrate surface toform one monolayer or less of titanium nitride due to the purge gasseparating the pulses 930 of the titanium containing compound 932 andpulses 920 of the nitrogen containing compound 922. In otherembodiments, the sequence of gas delivery may be varied to provide apartial self-limiting deposition process or a non-self-limitingdeposition process. For example, the pulse 930 of the titaniumcontaining compound 932 may be partially overlapped with the pulse 920of the nitrogen containing gas 922 to provide a combined mode ofdeposition (i.e. a combined adsorption process and gas-phase/thermalco-reaction process between the titanium containing compound and thenitrogen containing gas). In another example, the purge gas may onlypartially separate the pulses 930 of the titanium containing compound932 and the pulses 920 of the nitrogen containing gas 922.

It is understood that the titanium containing compound 932 may also beother titanium based precursors, such as other titanium based precursorsdisclosed elsewhere herein. Examples of other nitrogen containing gases922 which may also be used include, but are not limited to, N_(x)H_(y)with x and y being integers (e.g., hydrazine (N₂H₄)); and other gases orgas mixtures containing nitrogen. For the deposition of a refractorymetal nitride layer comprising tantalum nitride, a tantalum containingcompound is used, such as the tantalum containing compounds describedelsewhere herein. For the deposition of a refractory metal nitride layercomprising tungsten nitride, a tungsten containing compound is used,such as the tungsten containing compounds described elsewhere herein.

C. Plasma-Enhanced Chemical Vapor Deposition of a Refractory Metal Layerand/or a Refractory Metal Nitride Layer

Chamber 100 may be used to deposit a refractory metal layer and/or arefractory metal nitride layer by plasma-enhanced chemical vapordeposition. For clarity reasons, deposition of a refractory metal layerand/or a refractory metal nitride layer will be described in more detailin reference to one embodiment of deposing a titanium layer.

Plasma-enhanced chemical vapor deposition of a titanium layer maycomprise introducing a titanium-containing compound, such as titaniumtetrachloride (TiCl₄), and introducing a hydrogen containing gas, suchas hydrogen gas (H₂) in chamber 100.

In one embodiment, referring to FIG. 2, a plasma is generated from thehydrogen containing compound between the top shower plate 160 and thebottom shower plate 170. The hydrogen containing gas may be introducedthrough the outer gas channels 143 of the gas distribution system 130and through the top shower plate 160. A plasma power may be provided tothe top shower plate 160 and the bottom shower plate 170 may be groundedto provide a hydrogen plasma from the hydrogen containing gas betweenthe top shower plate 160 and the bottom shower plate 170. The hydrogenplasma travels through the column holes 183 of the bottom shower plate170 to the substrate receiving surface 111. The titanium containingcompound may be introduced through the central gas channel 137 of thegas distribution system 130, through the gas conduit 210 (FIG. 3), andthrough the groove holes 185 of the bottom shower plate 170 (FIG. 3) tothe substrate receiving surface 111.

The titanium containing compound and the hydrogen containing compoundare introduced separately through discrete paths through the gasdistribution system 130 of chamber 100 to reduce the likelihood ofreaction of the hydrogen plasma and the titanium containing compoundwithin the gas distribution system 130 and the formation of particleswithin the gas distribution system.

In another embodiment, still referring to FIG. 2, a plasma is generatedfrom gas between the bottom shower plate 170 and the substrate support112. A plasma power may be provided to the top shower plate 160 and thebottom shower plate 170 so that the plates are at the same orsubstantially same potential and the substrate support 112 is groundedso that the top and bottom shower plates 160, 170 act as the powerelectrode and the substrate support 112 acts as the ground electrode ingenerating a plasma from gases therebetween. The hydrogen containingcompound and the titanium containing compound may be introducedseparately through discrete paths through the gas distribution system.For example, the hydrogen containing compound may be introduced throughthe outer gas channels 143 and the titanium containing compound may beintroduced through the central gas channel 137 of the gas distributionsystem 130. In another example, the hydrogen containing compound may beintroduced through the central gas channel 137 and the titaniumcontaining compound may be introduced through the outer gas channels 143of the gas distribution system 130. Alternatively, the hydrogencontaining compound and the titanium containing compound may beintroduced together through the gas distribution system 130 through thecentral gas channel 137 and/or through the outer gas channels 142.

FIG. 9 is a graph of one exemplary process illustrating the controlsignals for plasma-enhanced chemical vapor deposition of a titaniumlayer. As shown in FIG. 9, a hydrogen containing gas 1022 and thetitanium containing compound 1032 may be continuously provided tochamber 100 whether separately through discrete paths through the gasdistribution system 130 or together through the gas distribution system130. The plasma power 1042 may be continuously provided to the powerelectrode whether the top shower plate 160 acts as the power electrodeor whether the top shower plate 160 and the bottom shower plate 170 acttogether as the power electrode.

It is understood that the titanium containing compound 1032 may also beother titanium based precursors, such as the titanium containingcompounds described elsewhere herein. The hydrogen containing gas 1022may also be other reducing gases, such as the other reducing gasesdescribed elsewhere herein. For the deposition of a refractory metallayer comprising tantalum, a tantalum containing compound is used, suchas the tantalum containing compounds described elsewhere herein. For thedeposition of a refractory metal layer comprising tungsten, a tungstencontaining compound is used, such as the tungsten containing compoundsdescribed elsewhere herein.

Plasma-enhanced chemical vapor deposition of a refractory metal nitridelayer would follow a similar process as plasma-enhanced chemical vapordeposition of a refractory metal layer. For example, plasma-enhancedchemical vapor deposition of a titanium nitride layer may compriseintroducing a titanium-containing compound, such as titaniumtetrachloride (TiCl₄), and introducing a hydrogen/nitrogen containinggas, such as a mixture of hydrogen gas (H₂) and nitrogen gas (N₂) inchamber 100 (FIG. 2). A plasma may be generated between the top showerplate 160 and the bottom shower plate 170 or may be generated betweenthe bottom shower plate 170 and the substrate support 112. It isunderstood that the titanium containing compound may also be othertitanium based precursors, such as the titanium containing compoundsdescribed elsewhere herein. Examples of other hydrogen/nitrogencontaining gases which may also be used to generate a hydrogen/nitrogenplasma include, but are not limited to, ammonia (NH₃), N_(x)H_(y) with xand y being integers (e.g., hydrazine (N₂H₄)); a mixture of hydrogengas, nitrogen gas, and ammonia; other combinations thereof; and othergases or gas mixtures containing hydrogen and nitrogen. For thedeposition of a refractory metal nitride layer comprising tantalumnitride, a tantalum containing compound is used, such as the tantalumcontaining compounds described elsewhere herein. For the deposition of arefractory metal nitride layer comprising tungsten nitride, a tungstencontaining compound is used, such as the tungsten containing compoundsdescribed elsewhere herein.

D. Combination of Cyclical Layer Deposition and Plasma-Enhanced ChemicalVapor Deposition

Chamber 100 may be used to deposit a refractory metal and/or arefractory metal nitride layer by a process similar to the combinationof cyclical layer deposition and plasma-enhanced chemical vapordeposition. For clarity reasons, deposition will be described in moredetail in reference to one embodiment of depositing a refractory metallayer comprising a titanium layer.

FIG. 10 is a graph of one exemplary process illustrating the controlsignals for a combination of cyclical layer deposition andplasma-enhanced chemical vapor deposition of a titanium layer. As shownin FIG. 10, one cycle 1110 comprises providing a continuous flow 1120 ofhydrogen containing gas 1122, such as hydrogen gas, to chamber 100 (FIG.2) through the outer gas channels 143 (FIG. 2), through the top showerplate 160, and through the column holes 183 of the bottom shower plate170 (FIG. 3) to the substrate receiving surface 111 (FIG. 2). During thecontinuous flow 1120 of hydrogen containing gas 1122, a pulse 1130 of atitanium containing compound 1132, such as TiCl₄, is introduced tochamber 100 (FIG. 2) through the central gas channel 137 (FIG. 2) of thegas distribution system 130, through the gas conduit 210 (FIG. 3), andthrough the groove holes 185 of the bottom shower plate 170 (FIG. 3) tothe substrate receiving surface 111 (FIG. 2). Also, during thecontinuous flow 1120 of the hydrogen/nitrogen containing gas 1122,pulses 1140 of plasma power 1142, such as an RF power, is provided toboth the top shower plate 160 and the bottom shower plate 170 (FIG. 2)to generate a hydrogen plasma from the flow 1120 of the hydrogencontaining gas 1122 between the bottom shower plate 170 and thesubstrate support 112 (FIG. 2). One or more of the pulses 1140 of plasmapower may overlap with the pulse 1130 of the titanium containingcompound 1132 and one or more the pulses 1140 of plasma power may beprovided separate from the pulse 1130 of the titanium containingcompound 1132. Alternatively, during the continuous flow 1120 of thehydrogen containing gas 1122, pulses 1140 of plasma power 1142, such asan RF power, is provided to the top shower plate 160 (FIG. 2) togenerate a hydrogen plasma from the flow 1120 of the hydrogen containinggas 1122 between the top shower plate 160 and the bottom shower plate170 (FIG. 2). The cycle 1110 may be repeated to a desired thickness ofthe titanium nitride layer.

In one aspect, a hydrogen plasma and a titanium containing compound isbeing provided at separate times to the substrate receiving surface 111to provide a deposition process similar to cyclical layer depositionwhich provides good conformal coverage over substrate structures. Inanother aspect, a hydrogen plasma and a titanium containing compound isbeing provided at the same time to the substrate receiving surface 111to provide a deposition process similar to plasma-enhanced chemicalvapor deposition which provides a high deposition rate.

It is understood that the titanium containing compound 1132 may also beother titanium based precursors, such as the titanium containingcompounds described elsewhere herein. The hydrogen containing gas 1122may also be other reducing gases, such as the other reducing gasesdescribed elsewhere herein. For the deposition of a refractory metallayer comprising tantalum, a tantalum containing compound is used, suchas the tantalum containing compounds described elsewhere herein. For thedeposition of a refractory metal layer comprising tungsten, a tungstencontaining compound is used, such as the tungsten containing compoundsdescribed elsewhere herein.

Combined cyclical layer deposition and plasma-enhanced chemical vapordeposition of a refractory metal nitride layer would follow a similarprocess as that for deposition of a refractory metal layer. For example,combined cyclical layer deposition and plasma-enhanced chemical vapordeposition of a titanium nitride layer may comprise introducing atitanium-containing compound, such as titanium tetrachloride (TiCl₄),and introducing a hydrogen/nitrogen containing gas, such as a mixture ofhydrogen gas (H₂) and nitrogen gas (N₂) in chamber 100 (FIG. 2). Pulsesof plasma power may be provided to the top shower plate 160 and thebottom shower plate 170 to generate pulses of plasma between the bottomshower plate 170 and the substrate support 112 or pulses of plasma powermay be provided to the top shower plate 160 to generated pulses ofplasma between the top shower plate 160 and the bottom shower plate 170.One or more of the pulses of plasma power may overlap with the pulse1130 of the titanium containing compound 1132 and one or more of thepulses 1140 of plasma power may be provided separate from the pulse 1130of the titanium containing compound 1132. The combined cyclical layerdeposition and plasma-enhanced chemical vapor deposition of a refractorymetal nitride layer provides both good conformal coverage and a highdeposition rate.

It is understood that the titanium containing compound may also be othertitanium based precursors, such as the titanium containing compoundsdescribed elsewhere herein. Examples of other hydrogen/nitrogencontaining gases which may also be used to generate a hydrogen/nitrogenplasma include, but are not limited to, ammonia (NH₃), N_(x)H_(y) with xand y being integers (e.g., hydrazine (N₂H₄)); a mixture of hydrogengas, nitrogen gas, and ammonia; other combinations thereof; and othergases or gas mixtures containing hydrogen and nitrogen. For thedeposition of a refractory metal nitride layer comprising tantalumnitride, a tantalum containing compound is used, such as the tantalumcontaining compounds described elsewhere herein. For the deposition of arefractory metal nitride layer comprising tungsten nitride, a tungstencontaining compound is used, such as the tungsten containing compoundsdescribed elsewhere herein.

E. Multiple Processes Performed in a Single Chamber

Chamber 100 as described in FIGS. 2-5 may be utilized to perform one ormore of the processes as described above to deposit one or more layersof materials over a substrate structure in a single chamber. FIG. 11 isa chart of exemplary embodiments of processes which may be performed inchamber 100. For clarity reasons, the chart shows processes for thedeposition of Ti and TiN, although other materials may be similarlydeposited. Chamber 100 may be used to perform one or more of theprocesses 2115 a-g in a single chamber. Other processes are alsopossible and other precursors may also be used. Chamber 100 may beutilized to perform in a single chamber one or more of the processesincluding, but not limited to, cyclical layer deposition of a refractorymetal layer 2115 a, combined cyclical layer deposition andplasma-enhanced chemical vapor deposition of a refractory metal layer2115 b, cyclical layer deposition of a refractory metal nitride layer2115 c, combined cyclical layer deposition and plasma-enhanced chemicalvapor deposition of a refractory metal nitride layer 2115 d,plasma-enhanced chemical vapor deposition of a refractory metal layer2115 e, plasma-enhanced chemical vapor deposition of a refractory metalnitride layer 2115 f, and/or chemical vapor deposition of a refractorymetal nitride layer 2115 g. The chamber 100 may switch from one processto another process by changing one or more parameters 2112 a-f, 2113a-f, 2114 a-f. Of course, other parameters may also be changed, whichinclude but are not limited to, flow rate of gases, substratetemperature, pressure of the chamber, etc.

For example, chamber 100 may be used to advantage to deposit in a singlechamber a titanium layer by cyclical layer deposition 2115 a and atitanium nitride by cyclical deposition 2115 c by changing the flow ofthe continuous flow of a hydrogen containing gas 2112 a to a continuousflow of a hydrogen/nitrogen containing gas 2112 d. The first gas source141 of chamber 100 of FIG. 2 may be adapted to provide varying amountsof a hydrogen containing gas, such as H₂, and a nitrogen containing gas,such as N₂, to deposit a refractory metal layer and a refractory metalnitride layer. Furthermore, the gas source may be adapted to graduallyor rapidly tune the composition of a refractory metal/refractory metalnitride layer. In another example, chamber 100 may be used to advantageto deposit in a single chamber a nucleation layer of a material bycyclical layer deposition and to deposit a bulk layer of the materialthereover by plasma-enhanced chemical vapor deposition or a combinationof cyclical layer deposition and plasma-enhanced chemical vapordeposition. In one aspect, performing two or more processes in a singlechamber increases the throughput of processing substrates.

F. Low Dielectric Constant Materials

Chamber 100 may be used to deposit a low dielectric constant material bycyclical layer deposition, chemical vapor deposition, or other suitabledeposition techniques. One example of a low dielectric constant materialis an oxidized organosilane or organosiloxane film. An oxidizedorganosilane or organosiloxane film may be deposited by sequentiallyproviding pulses of an organo silicon compound and pulses of anoxidizing agent. Alternatively, an oxidized organosilane ororganosiloxane film may be deposited by a continuous flow of an organosilicon compound and a continuous flow or pulses of an oxidizing agent.Examples of organo silicon compounds include methylsilane,dimethylsilane, triethylsilane, disilanozethane,bis(methyl-silano)methane, 1,2-disilanoethane,1,2-bis(methylsilano)ethane, 2,2-disilanopropane,1,3,5-trisilano-2,4,6-trimethylene, 1,3-dimethyldisiloxane,1,1,3,3-tetramethyldisiloxane, 1,3-bis(silanomethylene)di-siloxane,bis(1-methyldisiloxanyl)methane, 2,2-bis(1-methyl-disiloxanyl)propane,2,4,6,8-tetramethylcyclotetrasiloxane,2,4,6,8,10-pentamethyl-cyclopenta-siloxane,1,3,5,7-tetrasilano-2,6-dioxy-4,8-dimetylene,2,4,6-trisilanetetra-hydropyran, 2,5-disilanotetrahydrofuran,fluorinated carbon derivatives thereof, other suitable compounds, andcombinations thereof. Examples of oxidizing agents include oxygen,nitrous oxide, ozone, carbon dioxide, and water. Preferably, theoxidizing agents are dissociated, such as by a RF power. RF power can beprovided continuously or in pulses. A preferred oxidized organosilanefilm is produced by reaction of methylsilane, dimethylsilane, or1,1,3,3-tetramethyl-disiloxane, and nitrous oxide at a constant RF powerlevel or a pulsed RF power level.

G. Metal Oxides

Chamber 100 may be used to deposit metal oxides utilizing atomic oxygenby cyclical layer deposition, chemical vapor deposition, or othersuitable deposition techniques. Metal oxide layers include, but are notlimited to titanium oxides, aluminum oxides, zirconium oxides, hafniumoxides, lanthanum oxides, barium strontium titanates, strontium bismuthtantalates, and lead zirconium titanates, and composite layers utilizingsuitable metal containing compounds and suitable oxygen containingcompounds.

Applications

A refractory metal layer and/or a refractory metal nitride layer may beused to advantage in a variety of applications. The refractory metallayers and refractory metal nitride layers may be used separately (i.e.,a TiN layer for use as an electrode in capacitor structures) or may beused together (i.e., a Ti/TiN layer for use as a contact layer, anadhesion layer, and/or a liner/barrier layer for the deposition ofmaterials thereover). When a refractory metal layer and a refractorymetal nitride layer are used together, the layers may be deposited inthe same chamber or in separate chambers.

FIG. 12A is a schematic cross-sectional view of one embodiment of aspecific application utilizing a titanium layer and a titanium nitridelayer together at one stage in the fabrication of an integrated circuit.As shown in FIG. 12A, the film stack 1200 includes an underlyingsubstrate 1202, such as a semiconductor substrate, and includes a dopedsource/drain region 1204. A metal silicide layer 1206, such as atitanium silicide layer, nickel silicide layer, cobalt silicide layer,or tungsten silicide layer, may be formed over the region 1204. Adielectric layer 1208, such as a silicon dioxide layer or low-kdielectric material, may be formed over the metal silicide layer 1206.The dielectric layer 1208 may be patterned and etched to form anaperture exposing the metal silicide layer 1206. A liner/barrier layer1210 comprising a titanium layer 1212 and comprising a titanium nitridelayer 1214 may be formed over the aperture. A conductive layer 1222comprising a conductive material, such as tungsten, copper, aluminum,and combinations thereof, may be deposited over the liner/barrier layer1210. In other embodiments, the metal silicide layer may be formed overa transistor gate.

FIG. 12B is a schematic cross-sectional view of another embodiment of aspecific application utilizing a titanium layer and a titanium nitridelayer together at one stage in the fabrication of an integrated circuit.As shown in FIG. 12B, the film stack 1250 includes an underlyingsubstrate 1252, such as a semiconductor substrate, and includes a dopedsource/drain region 1254. A dielectric layer 1258, such as a silicondioxide layer, may be formed over the substrate 1252. The dielectriclayer 1258 may be patterned and etched to form an aperture. A titaniumlayer 1259 may be deposited over the aperture to form titanium silicide1256 in situ. A titanium nitride layer 1260 may be deposited over thetitanium layer 1259. A conductive layer 1262, such as a tungsten layer,may be deposited over the titanium nitride layer 1260. In otherembodiments, the titanium silicide may be formed over a transistor gate.

The titanium layer 1212, 1259 and the titanium nitride layer 1214, 1260may be deposited in the same chamber or in separate chambers. In oneembodiment, the titanium layer 1212, 1259 is deposited by cyclical layerdeposition while the titanium nitride layer 1214, 1260 is deposited bycyclical layer deposition. In another embodiment, the titanium layer1212, 1259 is deposited by cyclical layer deposition while the titaniumnitride layer 1214, 1260 is deposited by chemical vapor deposition orplasma-enhanced chemical vapor deposition. In still another embodiment,the titanium layer 1212, 1259 is deposited by cyclical layer depositionwhile the titanium nitride layer 1214, 1260 is deposited by acombination of cyclical layer deposition and chemical vapor depositionor a combination of cyclical layer deposition and plasma-enhancedchemical vapor deposition.

In another embodiment, cyclical layer deposition may be used toadvantage to deposit a refractory metal layer and/or a refractory metalnitride layer at a low temperature, such as 500° C. or less, over formeddevices, such as logic devices, which may begin to break down attemperature greater than 500° C.

While foregoing is directed to the preferred embodiment of the presentinvention, other and further embodiments of the invention may be devisedwithout departing from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. A substrate processing chamber, comprising: a top shower plate; abottom shower plate; a substrate support; an insulator disposed betweenthe top shower plate and the bottom shower plate; a power source coupledto the top shower plate, the bottom shower plate, or the substratesupport; and a controller adapted to control the power source to providepulses of power and to provide ground to the top shower plate, thebottom shower plate, or the substrate support.
 2. The substrateprocessing chamber of claim 1, wherein the power source coupled to thetop shower plate is adapted to generate pulses of plasma between the topshower plate and the bottom shower plate.
 3. The substrate processingchamber of claim 1, wherein the power source coupled to the substratesupport is adapted to generate pulses of plasma between the substratesupport and the bottom shower plate.
 4. The substrate processing chamberof claim 1, wherein the power source coupled to the top shower plate isadapted to generate pulses of plasma between the top shower plate andthe substrate support.
 5. The substrate processing chamber of claim 1,wherein the power source coupled to the bottom shower plate is adaptedto generate pulses of plasma between the bottom shower plate and thesubstrate support.
 6. The substrate processing chamber of claim 1,wherein the power source coupled to the bottom shower plate is adaptedto generate pulses of plasma between the bottom shower plate and the topshower plate.
 7. The substrate processing chamber of claim 1, whereinthe power source coupled to the substrate support is adapted to generatepulses of plasma between the substrate support and the top shower plate.8. The substrate processing chamber of claim 1, wherein the controlleris adapted to control the power source to provide pulses of power. 9.The substrate processing chamber of claim 1, wherein the controller isadapted to control the power source to selectively provide pulses ofpower and a continuous flow of power.
 10. The substrate processingchamber of claim 1, further comprising a switch device coupling thepower source and a grounding device to the bottom shower plate.
 11. Thesubstrate processing chamber of claim 1, wherein the power source isadapted to selectively provide pulses or a continuous flow of power tothe bottom shower plate.
 12. A substrate processing chamber, comprising:a gas processing region defined by a top shower plate, a bottom showerplate and an insulator; a substrate processing region defined by thebottom shower plate, a substrate support, and chamber walls; a powersource and ground coupled to the top shower plate, the bottom showerplate, or the substrate support; and a controller adapted to control thepower source and a ground to generate a pulse of plasma in the gasprocessing region, the substrate processing region, or both the gasprocessing and substrate processing regions.
 13. The substrateprocessing chamber of claim 12, wherein the power source coupled to thetop shower plate is adapted to generate pulses of plasma between the topshower plate and the bottom shower plate.
 14. The substrate processingchamber of claim 12, wherein the power source coupled to the substratesupport is adapted to generate pulses of plasma between the substratesupport and the bottom shower plate.
 15. The substrate processingchamber of claim 12, wherein the power source coupled to the top showerplate is adapted to generate pulses of plasma between the top showerplate and the substrate support.
 16. The substrate processing chamber ofclaim 12, wherein the power source coupled to the bottom shower plate isadapted to generate pulses of plasma between the bottom shower plate andthe substrate support.
 17. The substrate processing chamber of claim 12,wherein the power source coupled to the bottom shower plate is adaptedto generate pulses of plasma between the bottom shower plate and the topshower plate.
 18. The substrate processing chamber of claim 12, whereinthe power source coupled to the substrate support is adapted to generatepulses of plasma between the substrate support and the top shower plate.19. The substrate processing chamber of claim 12, wherein the controlleris adapted to control the power source to provide pulses of power. 20.The substrate processing chamber of claim 12, wherein the controller isadapted to control the power source to selectively provide pulses ofpower and a continuous flow of power.
 21. The substrate processingchamber of claim 12, further comprising a switch device coupling thepower source and a grounding device to the bottom shower plate.
 22. Thesubstrate processing chamber of claim 12, wherein the power source isadapted to selectively provide pulses or a continuous flow of power tothe bottom shower plate.
 23. A substrate processing chamber, comprising:a top shower plate; a bottom shower plate; an insulator disposed betweenthe top shower plate and the bottom shower plate; a substrate support; apower source coupled to the top shower plate, the bottom shower plate,or the substrate support; a gas delivery system; and a controlleradapted to control the gas delivery system to provide pulses of gas andto control the power source and a ground to provide pulses of power andto provide ground the top shower plate, the bottom shower plate, or thesubstrate support.
 24. The substrate processing chamber of claim 23,wherein the power source coupled to the top shower plate is adapted togenerate pulses of plasma between the top shower plate and the bottomshower plate.
 25. The substrate processing chamber of claim 23, whereinthe power source coupled to the substrate support is adapted to generatepulses of plasma between the substrate support and the bottom showerplate.
 26. The substrate processing chamber of claim 23, wherein thepower source coupled to the top shower plate is adapted to generatepulses of plasma between the top shower plate and the substrate support.27. The substrate processing chamber of claim 23, wherein the powersource coupled to the bottom shower plate is adapted to generate pulsesof plasma between the bottom shower plate and the substrate support. 28.The substrate processing chamber of claim 23, wherein the power sourcecoupled to the bottom shower plate is adapted to generate pulses ofplasma between the bottom shower plate and the top shower plate.
 29. Thesubstrate processing chamber of claim 23, wherein the power sourcecoupled to the substrate support is adapted to generate pulses of plasmabetween the substrate support and the top shower plate.
 30. Thesubstrate processing chamber of claim 23, wherein the controller isadapted to control the power source to provide pulses of power.
 31. Thesubstrate processing chamber of claim 23, wherein the controller isadapted to control the power source to selectively provide pulses ofpower and a continuous flow of power.
 32. The substrate processingchamber of claim 23, further comprising a switch device coupling thepower source and a grounding device to the bottom shower plate.
 33. Thesubstrate processing chamber of claim 23, wherein the power source isadapted to selectively provide pulses or a continuous flow of power tothe bottom shower plate.